1. Field of the Invention
This invention relates to intentional burning, often called ‘prescribed burning’ for wild-land and wildlife management purposes, and in particular to an apparatus for launching incendiary spheres for the purpose of conducting such prescribed burning.
2. Brief Description of the Related Art
Prescribed burning is a common activity that is well recognized to produce many wild-land, environmental, agricultural and wildlife benefits. A variety of methods and devices are employed to do this. One main methodology uses flammable liquid or, flammable sludge, which is ignited as it exits the ignition device. Examples of such devices range from hand held ‘drip torches’ to helicopter slung ‘heli-torches’, or to vehicle-mounted or vehicle-towed devices, often called ‘terra-torches’, which eject ignited fuel under pressure much as does a military-type flamethrower. All flammable liquid methods carry with them certain disadvantages. The first such disadvantage is the obvious potential danger to the personnel who operate these devices. Such danger may arise for instance as an unintended consequence of misdirected flame, or possibly by explosion. Secondly, although such devices are effective for starting fires, they tend to consume a large quantity of fuel relative to both the number of fires they start, and to the total area they burn; consequently there exists an ongoing need to re-fuel these devices, which includes the storage, transportation, and often mixing of fuel, which imposes a significant operational challenge in the field. This re-fueling requirement also adds environmental risk and significant expense. Thirdly, there exist several physical limitations regarding the design, construction, and operation of any mechanical device which processes and ignites flammable liquids. Such limitations can be related for instance to the need to avoid fuel or flame leakage, or to mitigate the consequences if such leakage occurs, or to other design restrictions due to the potentially detrimental effect of burning fuel upon the mechanical or electrical components of the device. These are some of the reasons why it is desirable to design and employ an ignition apparatus which processes neither flammable liquid, nor flame itself.
One existing method of igniting prescribed burns which avoids the need to emit ignited liquids is that commonly referred to as ‘delayed ignition’. The most common method of delayed ignition is a machine that processes plastic incendiary spheres. Such a machine is known as a “plastic sphere dispenser” (PSD). Each plastic sphere is partly filled with an incendiary such as potassium permanganate, and, as the sphere is processed within the machine it is injected with a reactant such as ethylene glycol. As a result, after a delay of about 20-40 seconds, the now-mixed chemicals react with one another to create flame, which then causes the plastic sphere to burn. This burning sphere becomes the source of ignition for whatever ground material is intended to be burnt. The main advantage of delayed ignition is the delay itself. This is what allows for a method, or device, that does not have to process actual flame with all of the difficulties associated with doing so, but rather it processes what can be referred to as a ‘pre-flame’ incendiary sphere. This ‘delayed ignition’ technique is the method referenced in the present invention.
It is often desirable to conduct prescribed burning from the air. This is especially true if the terrain is difficult or impossible to traverse by ground, or if the area to be burnt is very large, in which case the time required to do so by traditional ground based methods may exceed the time window within which optimal burning conditions (wind speed and direction, temperature, relative humidity, etc.) can be expected to persist. When prescribed burning is conducted from the air, this is usually done by helicopter. This can be done by ‘Heli-torch’ as previously mentioned, or, it can be done by installing a PSD within the cabin of the helicopter. A PSD is capable of producing ‘charged’, or injected spheres, which are dropped by gravity from the aircraft to the ground. There are presently several PSD machines on the market, to site the four known such devices by their marketing name, they are: the ‘Mark III’, the ‘Red Dragon™’ (US 2010101401 A1), the Mark V′ and the ‘Spitfire’™ (CA 2,761,242/U.S. patent application Ser. No. 14/061,511, now U.S. Pat. No. 9,199,735 B2). There exist other devices which dispense delayed-ignition capsules such as the Raindance R2 (U.S. Pat. No. 7,451,679 B2) but these are not relevant to this general discussion because they do not dispense incendiaries that are sphere shaped.
All of the above PSD machines however are restricted by their design in that, by themselves, they can only practically be used by helicopter. Were it attempted to deploy one by ground vehicle the consequence would be of very little practical benefit. This is because the PSD machine, by itself, is not capable of launching the charged incendiary for a distance; it can only drop it straight down by gravity. This is perfectly acceptable and practical of course when using the PSD by helicopter because it is merely a matter of maneuvering the helicopter directly over the area that is desired to be burned, but the same machine, if deployed by ground vehicle, would only drop the incendiary right on the trail that the vehicle is travelling on. In nearly every case it is not the trail itself that is desired to be burned but the area beside the trail; this desired adjacent area could be anywhere from a few feet away to a hundred feet or more from the trail. This therefore explains the rationale for the present invention; namely: to provide an apparatus which will receive a charged incendiary from a PSD machine and then launch it for a distance, thus allowing a helicopter-deployed PSD machine to also be used by ground vehicle. Given the fact that an incendiary, once charged is about to burst in flame in about 25 seconds time, and another one is normally coming right behind it, the launcher must operate quickly and it must operate jam free. It must also be capable of reliably processing incendiaries no matter what rate (expressed in balls per minute or “BPM”) they are received by it. In the preferred embodiment for instance the present invention is capable of launching incendiaries at any rate between 1 and 200 BPM, which of course is a very widely varied BPM range, a greater range than any existing PSD machine is capable of producing.
As will be seen, the present invention launches the incendiary by means of contact with a spinning wheel, or wheels. The applicant recognizes a large number of devices exist which launch a sphere, or ball by means of contact with a spinning wheel or wheels, however, the applicant is not aware of such devices being used to launch an incendiary sphere. The majority of the known ball launchers relate to some sporting activity that employs, as of course many do, some type of ball. For the most part, these sport ball throwers launch balls for the purpose of practice or training. It seems that for every sport that uses a ball there is a mechanical machine that can be used to launch that ball in series for practice or training purposes. This is certainly true for tennis, baseball, softball, basketball and football (often called ‘soccer’ in North America). Tennis is particularly well represented in the category of ball throwing machines that employ spinning wheels to launch the balls: the Lobster Company produces several models including ELITE series and GRAND series; there is also the Silent Partner Company which produces the LITE, the SPORT, and the STAR, and there are several other companies which produce similar products. Spinning wheel machines are also used with baseballs, softballs, basketballs and soccer balls. In the case of baseballs and softballs it is also known to employ only a single wheel in combination with a ‘kick plate’ which biases the ball against the spinning wheel, as opposed to the much more common two-wheel configuration used in the vast majority of sport ball throwers.
Therefore, while it is recognized that there are a great variety and quantity of machines, especially sport ball throwers in existence which do employ a spinning wheel or wheels to convey velocity to a sphere, no existing spinning-wheel machine of any description launches charged incendiary spheres, and this is despite the fact that delayed-ignition incendiary spheres have been in use for prescribed burning for about 25-30 years now. Also, it must be emphasized that the technical performance requirements for an incendiary sphere launcher in comparison to a sport ball thrower are of an altogether more exacting, critical and challenging nature. No tennis expert needs to be trained to handle three balls per second, and no sport ball will burst on fire if it jams or backlogs inside the throwing machine. The unique mechanisms which the present invention employs in order to ensure the required speed, precision and reliability of sphere handling are the inclusion of a ‘delivering wheel’ which operates in combination with a spring-loaded ‘lower rail’ and tapered-tip ‘side walls’. These features are more fully described in the paragraphs that follow.
The above discussion addresses machines that launch spheres, excluding incendiary spheres, by means of contact with spinning wheels, but this is not to say that there exists no machines that launch charged incendiaries. A series of delayed-ignition devices are produced by Field Support Services of Atlanta, Ga. The PyroShot™ (U.S. Pat. No. 7,275,529) is a spring loaded ‘hand launcher for ground ignition’ which indicates, of course, that it is intended for use by personnel while walking on foot. The same company has also produced an HS model which includes a CO2 tank for the purpose of propelling the charged sphere for a longer distance. Further, the same company, in partnership with another company has recently introduced its Green Dragon™ product (U.S. Pat. No. 8,316,750/CA 2,703,398). The Green Dragon also employs pressurized CO2 to launch each sphere over a long distance, and this is normally mounted on a truck or a UTV type vehicle as opposed to being used by a person on foot. All three products (hereafter referred to as PyroShot) are intended exclusively for use by ground, as opposed to aerial, deployment, and all three are used independently of a PSD. To be clear on this last point it should be explained that the term PSD (meaning: Plastic Sphere Dispenser) has become commonly used to describe those four previously mentioned machines that drop incendiary spheres from a helicopter. Strictly speaking PyroShot could just as rightly be referred to as a PSD, because it does in fact dispense-plastic-spheres; the PyroShot includes all the mechanisms necessary to inject the incendiary sphere with reactant before it launches it. Thus, a main differentiation between PyroShot and the present invention is that PyroShot is a stand-alone gun, or system, which maneuvers, injects and then launches incendiary spheres, while the present invention is an apparatus that is exclusively used only to receive charged incendiaries from an existing PSD machine and then launch them. Most significantly, in consideration of the main job that the present invention is designed to do, namely the launching of incendiary spheres, there are no obvious similarities between PyroShot and the present invention in the manner in which they accomplish that task. PyroShot employs either a spring release, or, gas pressure for motive power to launch the incendiary sphere, whereby the present invention employs spinning wheels to do so.
The applicant is aware of no other relevant art in addition to that as described above.